Single reel tape cartridge with tape reel centering features

ABSTRACT

The single reel tape cartridge with tape reel centering features provides one or more features to center the tape reel with respect to the interior surfaces of the tape cartridge housing and a rotatably driven feature, such as a drive chuck, in the tape drive that rotates the tape reel. The single reel tape cartridge with tape reel centering features provides mechanical positioning and centering of the tape reel with respect to the drive chuck of the tape drive when the tape cartridge is in any orientation and constrains lateral movement of the tape reel to prevent the tape reel from contacting the interior surfaces of the tape cartridge housing. This is accomplished by the use of a spring that applies a bias force to press the tape reel against the drive chuck in the tape drive, which rotates the tape reel. One end of the spring is seated in a spring sleeve that is formed in the center of the interior surface of the top section of the tape cartridge housing. The other end of the spring engages the tape reel.

FIELD OF THE INVENTION

[0001] The invention relates to single reel tape cartridges that areused in tape drive storage devices, and in particular, to a single reeltape cartridge having tape reel centering features.

Problem

[0002] It is a problem in the field of single reel tape cartridges thatare used in tape drive storage devices to facilitate the positioning andcentering of the tape reel, located within the tape cartridge, withrespect to the drive chuck of the tape drive. The tape drive chuckrotates to impart rotational motion to the tape reel by the use offeatures on the tape drive chuck (teeth, spline, pins, etc.) that matewith corresponding features on the hub of the tape reel. The rotation ofthe tape reel causes movement of the magnetic tape wound on the tapereel to or from the take-up reel that is located within the tape drive.Accurate positioning and centering of the tape reel within the tapecartridge and with respect to the tape drive chuck is desirable toensure effective engagement between the hub of the tape reel and thetape drive chuck. Existing single reel tape cartridges fail to provide ahigh degree of accuracy in aligning the tape reel with the drive chuck,often resulting in the engaging features impacting each other for aperiod of time rather than engaging each other to rotate the tape reel.In addition, a further aspect to the tape reel centering problem is thatunconstrained lateral movement of the tape reel within the tapecartridge housing often results in damage to the tape reel if the tapecartridge is dropped and the tape reel impacts the interior surface ofthe tape cartridge housing.

[0003] This tape reel centering problem is exacerbated when the tapecartridge is oriented on its side (i.e. gravitational forceperpendicular to the tape reel axis). Existing tape cartridges weredesigned to function in a flat orientation (gravity parallel to tapereel axis). When these existing tape cartridges are used in a verticalorientation, they experience failures due to the fact that they were notdesigned for this type of function and the tape reel is not properlylocated within the tape cartridge housing. Tape cartridge libraries,automatic tape cartridge loading devices, and robotic tape cartridgehandling apparatus frequently orient the tape drives vertically (ontheir sides) and encounter failures of the tape reel drive feature toengage with the mating drive feature located on the drive chuck of thetape drive.

Solution

[0004] The present single reel tape cartridge with tape reel centeringfeatures overcomes the problems outlined above and advances the art byproviding a magnetic tape reel that is equipped with one or morefeatures to center the tape reel with respect to the interior surfacesof the tape cartridge housing and a rotatably driven feature, such as adrive chuck, in the tape drive that rotates the tape reel. The singlereel tape cartridge with tape reel centering features providesmechanical positioning and centering of the tape reel with respect tothe drive chuck of the tape drive when the tape cartridge is in anyorientation and constrains lateral movement of the tape reel to preventthe tape reel from contacting the interior surfaces of the tapecartridge housing.

[0005] This is accomplished by the use of a spring that applies a biasforce to press the tape reel against the drive chuck in the tape drive,which rotates the tape reel. One end of the spring is seated in a springsleeve that is formed in the center of the interior surface of the topsection of the tape cartridge housing. The other end of the springengages the tape reel. Centering of the tape reel within the tapecartridge housing and with respect to the drive chuck is also achievedwith by use of a tape reel hub-centering feature. This tape reelhub-centering feature consists of a chamfered centering ring thatencircles the drive teeth formed on the tape reel to engage the drivechuck. The chamfered centering ring fits into a chamfer that is formedin the circumference of the drive chuck access hole located in thebottom of the tape cartridge housing. A cylindrically-shaped tape reellocator boss is also formed in the center of the inside of the topsection of the tape cartridge housing. The tape reel locator boss mateswith the tape reel center bore formed in the tape reel hub. The tapereel locator boss can include a chamfer formed on its rim to enablesmooth engagement of the tape reel locator boss with the mating tapereel center bore. In addition, a plurality of ramped centering posts canbe used in the tape cartridge housing to form a channel by which thedrive teeth formed on the tape reel are guided into alignment with thedrive chuck. In operation, the ramped centering posts serve to funnelthe tape reel into a substantially centered position within the tapecartridge housing so that the drive teeth of the tape reel are centeredwith respect to the drive chuck access hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 illustrates a typical tape drive that is adapted to loadsingle reel tape cartridges for the reading and writing of data onrewriteable media stored in the single reel tape cartridges;

[0007]FIG. 2 illustrates a typical single reel tape cartridge and theinterconnection of the rewriteable media stored therein with a leaderattached to the take-up reel of the tape drive; and

[0008]FIGS. 3 and 4 illustrate in bottom and top perspective views,respectively, an exploded representation of the single reel tapecartridge with tape reel centering features.

DETAILED DESCRIPTION OF THE DRAWINGS

[0009] For purposes of illustration and not of limitation, variousfeatures and advantages of the present invention will now be describedwithin the context of a single reel DLT tape cartridge. It is to beunderstood that the following description with respect to a DLT tapecartridge is not intended to limit the scope of the present invention.It would be obvious to one skilled in the art that the principles of thepresent invention could be easily applied to other tape cartridgeformats.

[0010]FIG. 1 illustrates one example of a typical tape drive 100. Thetape drive 100 is a DLT tape drive that employs a single reel DLT tapecartridge. This design includes a supply reel located within a tapecartridge (not shown) and a take-up reel 101 located within the tapedrive 100. Referring to FIG. 2, the magnetic tape media in the tapecartridge is terminated at one end by a tape cartridge leader 201. Thetape cartridge leader 201 is a strong flexible plastic strip containingan ovular aperture 202 on its distal end. A take-up leader 203, thatconnects to the take-up reel 101, is a similar plastic strip thatincludes a stem 204 and tab 205 designed to buckle with the ovularaperture 202 on the tape cartridge leader 201 to form buckle 200. Thetape cartridge leader 201 also includes a section 206 that is slightlywider than the rest of the tape cartridge leader 201 and the take-upleader 203. The wider section 206 prevents the tape cartridge leader 201from being pulled into the tape cartridge after the tape cartridgeleader 201 and take-up leader 203 are disconnected for ejection of thetape cartridge.

[0011] Upon loading the tape cartridge into the tape drive 100, thetake-up leader 203 and tape cartridge leader 201 are buckled, and thetape media is wound to a start point or read position in the tape drive.To accommodate the slightly wider section 206 during winding of the tapecartridge leader 201 and the take-up leader 203 around the take-up reel101, the take-up reel 101 includes a wider stepped area 102 formed inthe top and in the bottom flanges, 112 and 113, of the take-up reel 101.

[0012]FIGS. 3 and 4 illustrate in bottom and top perspective views,respectively, an exploded representation of the single reel tapecartridge with tape reel centering features. The tape cartridge 300consists of a two-part housing that includes a top section 301 and abottom section 302 for enclosing the tape reel 310 and its associatedmagnetic tape (not shown). The tape reel 310 comprises a top flange 311connected to a top portion of a tape reel hub 312 and a bottom flange313 connected to a bottom portion of the tape reel hub 312. The tapereel hub 312 could be a conventional tape reel hub that connects to thetape drive in a conventional manner. The top and bottom flanges, 311 and313, are connected in a parallel relationship and form a magnetic tapemedia containment section 314 on the tape reel hub 312. The tape mediacontainment section 314 guides the tape media around the tape reel hub312 during operation of the tape drive. The tape cartridge 300 alsoincludes a write protect element 321 and magnetic tape access door 322.

[0013] It is desirable to have the tape reel 310 centered with respectto the drive feature to enable the drive teeth on the drive chuck on thetape drive to accurately and securely engage the drive teeth 315 on thetape reel 310. A drive chuck access hole 303 is formed in the bottomsection 302 of the tape cartridge housing to enable the drive chuck ofthe tape drive to engage the drive teeth 315 of the tape reel 310. Aspring 304 applies a bias force to press the tape reel 310 against thedrive feature (such as the drive chuck) in the tape drive when engagedto rotate the tape reel 310. In order to provide a bias force on thetape reel 310 in a manner to automatically center the tape reel 310 onthe drive teeth 315, one end of the spring 304 is seated in a springsleeve 306 that is formed in the center of the interior surface of thetop section 301 of the tape cartridge housing. The other end of thespring 304 engages the tape reel 310. The use of the spring sleeve 306reduces spring deflection in directions other than coaxial with the axisof the tape reel 310, thereby also reducing any lateral forces on thetape reel 310. This reduction of lateral forces serves to automaticallycenter the tape reel 310 on the drive teeth 315.

[0014] Centering of the tape reel 310 within the tape cartridge housingand with respect to the drive chuck is also achieved with by use of atape reel hub-centering feature. This tape reel hub-centering featureconsists of a chamfered centering ring 316 that encircles the driveteeth 315 formed on the tape reel 310 to engage the drive chuck. Thechamfered centering ring 316 fits into a chamfer 317 that is formed inthe circumference of the drive chuck access hole 303 located in thebottom of the tape cartridge housing. The chamfered centering ring 316seats in the chamfer 317 of the drive chuck access hole 303 to preciselyalign the drive teeth 315 formed on the tape reel 310 with the drivechuck.

[0015] The tape cartridge 300 is resistant to damage that can be causedby dropping the tape cartridge. The tape cartridge 300 is equipped witha cylindrically-shaped tape reel locator boss 305 that is formed in thecenter of the inside of the top section 301 of the tape cartridgehousing. The tape reel locator boss 305 mates with the tape reel centerbore 318 formed in the tape reel hub 312. In particular, the tape reelcenter bore 318 is a cylindrically-shaped opening of diameter greaterthan the diameter of the tape reel locator boss 305. The dimensions ofthe tape reel center bore 318 and tape reel locator boss 305 areselected to prevent lateral movement of the tape reel 310 where theflanges 311, 313 can impact the walls of the housing. The tape reellocator boss 305 can include a chamfer 307 formed on its rim to enablesmooth engagement of the tape reel locator boss 305 with the mating tapereel center bore 318. When the tape cartridge 300 is dropped, the tapereel locator boss 305 prevents the tape reel flanges 311, 313 fromimpacting the interior side walls of the cartridge housing 301, 302because the tape reel locator boss 305 is located within tape reelcenter bore 318 which limits the travel of the tape reel side to sidewithin the cartridge housing. In addition, a ring or ridge of raisedmaterial could be added to the inside top and/or wall of the cartridgehousing which prevents the tape reel flange(s) from impacting the insideof the cartridge housing due to motion along the axis of the tape reel310.

[0016] In addition, a plurality of ramped centering posts 331-334 can beused in the tape cartridge housing to form a channel by which the driveteeth 315 formed on the tape reel 310 are guided into alignment with thedrive chuck. In operation, the ramped centering posts 331-334 serve tofunnel the tape reel 310 into a substantially centered position withinthe tape cartridge housing so that the drive teeth 315 of the tape reel310 are centered with respect to the drive chuck access hole 303. Inaddition, when the tape cartridge is inserted in the tape drive, theaxes of the bias spring 304, tape reel 310, and drive chuck are largelycollinear. On occasion, however, the axis of the drive chuck and tapereel 310 are not collinear. This inhibits the proper engagement of thedrive teeth located on the drive chuck with the drive teeth 315 on thetape reel 310. The outside diameter of the drive chuck teeth is lessthan the inside diameter of the chamfered centering ring 316 by aspecific amount. If the inside face of the chamfered centering ring 316comes into contact with the outside diameter of the drive chuck teeththus providing a side-wards force is applied to the tape reel 310 toautomatically center it. Due to the angle and orientation of thechamfered centering ring 316, the tape reel 310 is biased to move into aposition where the axes of the tape reel 310 and drive chuck arecollinear. When these axes are collinear, the respective drive teeth ofthe drive chuck and tape reel are aligned, and have the best opportunityfor full and secure engagement.

[0017] In addition, if due to some other forces, the respective driveteeth of the drive chuck and tape reel were to become disengaged, thechamfered centering ring 316 would aid in the re-engagement of therespective drive teeth of the drive chuck and tape reel since thechamfered centering ring 316 would provide a physical and mechanicalbarrier against the axes of the tape reel 310 and drive chuck frombecoming substantially non-collinear.

Alternate Embodiments

[0018] The respective and mating drive teeth of the drive chuck and tapereel could alternatively be implemented as other mating features suchas, but not limited to, pin and hole configurations, matching splinetongue and groove configurations, or any other mating features thatwould facilitate transmitting a rotational force from a drive feature toa driven feature.

[0019] Those skilled in the art will appreciate variations of theabove-described embodiments that fall within the scope of the invention.As a result, the invention is not limited to the specific examples andillustrations discussed above, but only by the following claims andtheir equivalents.

What is claimed:
 1. A single reel tape cartridge that is configured tobe loadable into a tape drive to read and write data on rewriteablemedia that is wound on the single reel tape cartridge, the single reeltape cartridge comprising: a tape reel comprising: a hub, a first flangeconnected to a top of the hub, a second flange connected to a bottom ofthe hub in a parallel relationship with the first flange, wherein thefirst flange and the second flange define a tape containment sectionbetween said first and second flanges, connecting means, attached tosaid second flange, for engaging a drive chuck located in the tape driveto enable rotation of said drive chuck to cause rotation of said tapereel; spring means for applying a bias force on said hub to press saidtape reel against said drive chuck; and a housing for enclosing saidtape reel, comprising: spring centering means formed on an interiorsurface of said housing and aligned to receive said spring means forlimiting movement of said tape reel in directions that are perpendicularto said hub axis.
 2. The single reel tape cartridge of claim 1 whereinsaid spring centering means limits movement of said spring means indirections that are perpendicular to said hub axis.
 3. The single reeltape cartridge of claim 1 wherein said tape reel further comprises: acylindrically-shaped aperture formed in said hub and centered on saidaxis.
 4. The single reel tape cartridge of claim 3 wherein said housingfurther comprises: a cylindrically-shaped feature of diameter less thana diameter of said cylindrically-shaped aperture to prevent said firstand said second flanges from impacting interior surfaces of saidhousing.
 5. The single reel tape cartridge of claim 4 wherein saidhousing further comprises: a chamfer formed on a circumference of saidcylindrically-shaped feature for guiding said cylindrically-shapedfeature into said center bore cylindrically-shaped aperture.
 6. Thesingle reel tape cartridge of claim 1 wherein said housing furthercomprises: a plurality of ramped centering posts formed on an insidesurface of said housing to form a channel to funnel said tape reel intoa substantially centered position within the tape cartridge housing. 7.A single reel tape cartridge that is configured to be loadable into atape drive to read and write data on rewriteable media that is wound onthe single reel tape cartridge, the single reel tape cartridgecomprising: a tape reel comprising: a cylindrically-shaped hub having acylindrically-shaped center bore formed axially therein, a first flangeconnected to a top of the hub, a second flange connected to a bottom ofthe hub in a parallel relationship with the first flange, wherein thefirst flange and the second flange define a tape containment sectionbetween the first and second flanges, drive teeth located on said bottomof said hub for engaging a drive chuck located in the tape drive toenable rotation of said drive chuck to cause rotation of said tape reel;bias spring, having a body, a first end and a second end, for applying abias force via said first end on said hub to press said tape reelagainst said drive chuck; and a housing for enclosing said tape reel,comprising: a bottom section having an aperture formed therein to enableaccess to said drive teeth by said drive chuck, a top section having aspring centering sleeve formed on an interior surface of said topsection and aligned to receive said body and said second end of saidbias spring for limiting movement of said tape reel in directions thatare perpendicular to said hub axis.
 8. The single reel tape cartridge ofclaim 7 wherein said spring centering sleeve limits movement of saidbody of said bias spring in directions that are perpendicular to saidhub axis.
 9. The single reel tape cartridge of claim 7 wherein said tapereel further comprises: a cylindrically-shaped aperture formed in saidhub and centered on said axis.
 10. The single reel tape cartridge ofclaim 9 wherein said top section of said housing further comprises: acylindrically-shaped feature of diameter less than a diameter of saidcylindrically-shaped aperture to prevent said first and said secondflanges from impacting interior surfaces of said housing.
 11. The singlereel tape cartridge of claim 10 wherein said top section of said housingfurther comprises: a chamfer formed on a circumference of saidcylindrically-shaped feature for guiding said cylindrically-shapedfeature into said center bore cylindrically-shaped aperture.
 12. Thesingle reel tape cartridge of claim 7 wherein said top section of saidhousing further comprises: a plurality of ramped centering posts formedon an inside surface of said top section of said housing to form achannel to funnel said tape reel into a substantially centered positionwithin the tape cartridge housing.